Publicist Harry Clein had recently signed up director Hugh Wilson, hoping that Wilson's soon-to-be-released film, "Police Academy," would be a monster hit. So the late-night call, hinting of things to come, was discouraging: "Harry," said the caller, "I don't think your client is going to make a lot of money. His film isn't gross enough."

The Ladd Co., the studio behind "Police Academy," had similar worries. It had set out to make a cop-oriented "Animal House," and was somewhat abashed by the satiric, stylish product Wilson created. Privately, one executive complained to producer Paul Maslansky that it needed more flatulence, more slobbishness, more nudity.

Fortunately for the principals, critics roasted the film for its unsavory elements, ignored its quality -- and a major box-office hit was born. The last-minute jitters, however, were symptomatic of an industry-wide hysteria: a stampede to turn out low-budget teen-age comedies to flood studio coffers with hundreds of millions.

And if the industry wasn't already convinced of the sagacity of grinding out mindless goon shows, "Police Academy" was proof positive of the rewards of doing so. Made for $4.1 million in Toronto and costing about $4 million more to publicize and market, the film earned more than $120 million here and abroad between last March and Nov. 1.

Looking back on the "Police Academy" experience, with its mandatory nude shower scene and its obligatory sex and chase scenes, director Wilson mused, "I now think I could go into a studio front office and say, 'The principal of a school is really a bad guy, so the kids gang together and blow up his car!' And I could get a major development deal on just that. There's a lot of feeling at the studios that the biggest obligation to the audience is to blow up the principal's car."

Wilson's cynical criticism only scratched the surface. After one of the biggest cinematic gold rushes since the talkies came in, Hollywood's power elite were seduced by a get-rich-quick formula for gang comedies -- a recipe of raunch and simple-mindedness that caused them to order directors to make it stupid, make it leering and make it cheap.

Naturally there were divergent versions of the formula. For instance, Sean Cunningham, director of the archetypical teen-age genre classic "Spring Break," described his plan thus: "Kids get drunk. Kids get laid. Kids go home."

A critic for the The Times of London, having seen "Police Academy," "Caddyshack" and "Fast Times at Ridgemont High," reduced the formula to three succinct points: "Rule one: Kids must get even or actually destroy an authority figure. Rule two: There must be one outstandingly dirty comic scene on a par with 'Porky's' peephole vignette. And, Rule three: No shades on the shower, please?"

But, after viewing more than two dozen such comedies, it became obvious that there was a far more detailed formula guiding the genre -- a blueprint to make a billion. Minor variations aside, it went something like this:

* Take a fairly mangy circle of losers or misfits;

* Pit them against a dastardly but incredibly one-dimensional villain -- a man or woman who would have put silent film audiences to shame;

* Send the losers pell-mell on a crusade to have sex;

* Throw in a healthy dose of sexism personified by jiggling, giggling heroines so free with their charms that Hugh Hefner would rub his hands in glee;

* Leer at this harvest through a peephole, video camera system or open shower door;

* Try for a food fight as simple as the John Belushi mashed potatoes spew in "Animal House," or as elaborate as the punch bowl, sheet cake apocalypse of "Valley Girl";

* Add a cacophony of body sounds in Dolby; * Patch all this together with a jarring, obnoxious rock 'n' roll sound track and launch it on the marketplace as "This Year's 'Animal House.' "

Neal Israel, who cowrote "Police Academy" and "Bachelor Party" with former stand-up comic Pat Proft and who directed "Bachelor Party," prefers to call these elements "block comedy scenes."

"Perhaps the most recognizable was the obvious results of guys eating beans in 'Blazing Saddles,' " says Israel. "If you have four or five of these block comedy scenes in a teen-age comedy, you have a hit. If your block comedy scenes are very, very strong ones -- you have a blockbuster."

In Israel's "Bachelor Party" examples were the girl using cat chow as a party dip, and the implied oral sexual encounter between a young male partygoer and a transsexual.

"Some guys at the studio, when you go in to pitch a movie, want to hear these jokes first," Israel says. "We even had a discouraging meeting where the brass of a large studio wanted to hear only the five big jokes. They wouldn't even listen to the story."

It's no secret that marketing executives at 20th Century-Fox were overjoyed with "Porky's" because the plot could be summarized in a few choice words: "Six horny Florida teen-agers tumble into a series of misadventures climaxed by the trashing of a bayou whorehouse."

All but a literate few of the plots in the genre are equally simple. For example: "A wild and crazy guy falls in love with a high society girl, and then ridicules her ritzy parents" ("Bachelor Party"). Maslansky's original idea for "Police Academy" was little more than an unfinished sentence: "A bunch of misfit police cadets are almost washed out of the academy but succeed . . ."

Ingenue screenwriters caught on to the one-sentence salesmanship and got their foot in the door by using a few, carefully chosen words.

Such a sentence earned $3.2 million in financial backing for Kevin Brodie, son of veteran character actor Steve Brodie. A former child actor, Brodie, 26, came up with the following premise: "A group of sexy sorority girls, about to lose their house, are drilled by their housemother (a former Marine drill sergeant) as competitors in the International Mud Wrestling Tournament. Naturally, they win."

Brodie's plot, mindless and sexist as it was, failed to find financing in the Hollywood studio system. So the fledgling writer and would-be director took his few chosen words on the road, specifically to Oklahoma City where he wowed a group of oilmen. "I managed to raise the entire $3.2 million from a rather small group of financiers," said Brodie, who also tossed $100,000 of his own into the pot.

His film, "Mugsy's Girls," starring Ruth Gordon and a gaggle of shapely mud-wrestler types, was filmed in Las Vegas last summer. To date, however, no studio has been willing to distribute it. "But we have until next spring," said Brodie, whose film also includes a pot-smoking rabbit. "We want it out for Easter . . . naturally!"

It has been 12 years since Harold Ramis sat down at his typewriter and banged out the idea for "Animal House," the grandfather of the current genre. And it took him and cowriters Doug Kenney and Chris Miller five years to get the project off the ground.

"Porky's," another blockbuster, took even longer. Bob Clark began plotting "Porky's" in his head in 1972, the idea based on experiences Clark shared with five Florida high school buddies in the '50s. "Everyone who knew Bob knew that he was obsessed with doing this picture," says Roger Swaybill, who coauthored the script.

"When Bob was in bed with mono in the summer of 1979, he suddenly began dictating the story of 'Porky's' to me, and for four days he dictated into a cassette recorder. I was weeping with laughter."

There's little doubt that "Porky's," with its stereophonic burps and belches, its sloppy encounters and its lewd plays on words, awakened Hollywood to the gold to be mined from bathroom humor.

A Ladd Co. executive, interviewing Hugh Wilson as the prospective director of "Police Academy," asked him if he'd seen "Porky's" or other films of the genre. Wilson hadn't. Finally, painfully, the Ladd exec said, "Well, you must have seen 'Animal House.' Everybody saw 'Animal House!' "

"Not me," said Wilson.

Maslansky was an admirer of Wilson's work as producer and writer on the TV series "WKRP" and convinced the Ladd Co. to hire him anyway. But Maslansky also organized a one-man film festival to acquaint Wilson with the genre.

"I saw them all," chuckles Wilson. "And, overall, it was fairly discouraging. This immediately convinced me to cut down on the sleaze. I asked for, and got, the power to completely rewrite the Israel-Proft script. Maintaining that 'funny is money,' I wanted to go for real laughter rather than going for the elements such as sex and antiestablishment exploits. I wanted jokes which were rooted in reality."

At first, Wilson took a red pencil to what he felt were the most tasteless elements in the script. This plunged him instantly into a fight with Maslansky, who believed that lowbrow comedy would make "Police Academy" a hit. "He took a lot of the vulgarity out -- some of the very things I considered necessary," says Maslansky. "I worried that it was becoming more homogenized, and I told Hugh, 'Let's keep some of the flatulence in.' "

Wilson eventually convinced Maslansky and the Ladd Co. that "subtle is better." Said Wilson, "I realized that you carry grossness, rudeness and crudeness just so far before the audience finds it terribly repetitive and not so funny. After the enormous success of 'Police Academy,' I no longer believe that you have to show the female breast or make cruel ethnic jokes -- not to mention the rampant sexism. And you don't have to reproduce the sounds an overfed body makes."

Wilson came away from the project with a grudging admiration for the genre. "What's termed 'gross cinema' is very tricky business; it can blow up in your face."

Others agree. Some copycat films used all the elements -- including stolen scenes -- common to "Animal House," "Porky's" and "Fast Times at Ridgemont High," with disappointing results. Cannon Group's "Last American Virgin" featured a bumbling fatso trying to lose his virginity, a gross concert of body noises, nude cheerleaders, pimple jokes, a locker room peephole and a sequence in a Tijuana brothel. Still, it only grossed about $15 million. When it was first shown in Westwood Village (home to UCLA) to a college audience, much of the audience booed. Saturn International's "Goin' All the Way" included virtually all the comedy elements from "Porky's" and "Animal House" and earned a disappointing gross of about $12 million. "Zapped" brought in only about $12 million; "Spring Fever" earned less than $6 million; "My Tutor" took in approximately $12 million and "D.C. Cab" made around $13 million.

"It's far harder to make a hit film in this genre than you might think," says Israel, whose production company, the Israel-Proft Deal, has 10 films in development at four studios. "Part of our deal here at 20th Century-Fox is that we are reading scripts. And we have been bombarded with teen-age goon comedy scripts. I've never read so many scripts and treatments before and still, most people don't seem able to write a funny script."

What goes wrong? Proft elaborates: "People pick an institution, say a beauty school or fire department. Then they just fashion a script around that. We're getting institutions but no humor. The question you have to ask is, 'If you took the jokes out, would it still be funny? And if you think the hit scripts, the ones which make it, are raunchy, you should see the bad ones."

Proft and Israel believe the success of the "Police Academy" and "Bachelor Party" scripts depended on reality. "Bachelor Party," for example, is based on the misadventures surrounding a bachelor bash organized for Israel's brother Bob. "Some of the stuff was so bizarre we tossed it almost intact into the film," Israel says.

In the case of "Revenge of the Nerds," the screenwriters believe that 20th Century-Fox was out to do a quickie nerd-exploitation film. "The idea the studio had of a nerd was just someone who was good at computers, wore glasses and bumbled through life," says Jeff Buhai, who wrote the script with Steve Zacharias. The writers, friends since college, converted what might have been simple goon comedy into a film. With director Jeff Kanew, they created a bouquet of sensitive nerds and pitted them against a cluster of Nazified jocks. "I wanted to say something, not just make people laugh," Kanew says. "I don't think the studio felt this way at all . . . They hoped for just another mindless romp."

But Kanew wasn't above using sex to make his ultimate point. In a crucial scene, Robert Carradine, the head nerd, lures a blond cheerleader away from the WASP villain Ted McGinley and beds her down. "All in all, I think we created the Cadillac of the genre," Kanew concludes.

There was no doubt that the R rating given almost all these teen-age comedy films resulted from the rampant raunchiness portrayed. And most of the filmmakers involved see the R rating as crucial to the box office. "An R-rated film will undoubtedly sell more tickets than a PG," says Kanew. "R is simply more titillating."

Says "Police Academy" director Wilson, "Somebody at Warner Brothers, I don't remember who, came to me after an early screening and said that the film was an R in letter but certainly not in spirit. I could have worked around the sex scene, toned down a couple of words and walked off with a PG. But there was a sense at the Ladd Company and the studio that it should be R." Warner Bros. distributed the film for the Ladd Co.

Since 80 percent of the genre's audience is composed of teen-agers, it became obvious during the "Porky's" boom that enforcement of the R rating was a mockery.

A marketing executive at 20th said that parents usually accompany their children to the box office, buy their tickets and then escort them to the door. During the "Porky's" box-office boom the film's director, Bob Clark, told the Associated Press, "There are people all over the country taking their 9-year-olds to see this film."

Perhaps no other genre -- not even the horror of the late '70s -- has drawn such widespread critical derision. When "Police Academy" opened, for instance, Time called it "the shame of the nation this year."

Israel and Proft rankle at the harsh criticism. "We know the kind of stuff we do is considered very lowbrow," says Israel. "But we don't make films so that we can show them to our friends at the Academy of Motion Picture Arts and Sciences; we want to make films that make us laugh."

Even some of the studio executives who have to market the teen-age films are unhappy with their general mindlessness. Irving N. Ivers, president, worldwide marketing for MGM/UA Entertainment Co., says the success of "Porky's," which he helped market, and "Hot Dog -- the Movie," which he sold for MGM, indicates "a certain amount of brain death which may have occurred among our youth. You've got to remember that the kids paying the money to see these films were brought up on pointless, action-packed televison situation comedies. Why should we expect them to want anything better?"

Barry Glasser, a vice president for national publicity at Walt Disney Productions, says that part of the industry is pandering to the lowest level of the teen-age audience. "There is a real audience out there for something that relates to real life rather than the mindless popcorn movies which are being produced so often now. I believe our success with 'Splash,' which drew much of the same audience which saw 'Porky's,' proved that there is a desire for more warmth and humanity."

The esthetic Grand Canyon separating the gung-ho teen comedy audience from those who wouldn't be caught dead at a showing of "Bachelor Party" or "Nerds" has posed a ticklish problem for studio marketing executives.

Ivers and others say that new teen comedy sales plans must be built on four harsh facts of life that are perhaps peculiar to the genre. First, the films usually have no major stars who can show up on the prime-time talk shows. Second, the teen-agers cannot be reached by newspaper critics or by most newspaper ads -- they don't read. Third, the raunchy, leering scenes that bring them out in droves can barely be hinted at in TV spots. And fourth, the wrong word or shading in a commercial can cause adolescents to shun a movie like the plague.

When it comes to selling these films, word of mouth is king.

Tom Sherak, president, domestic distribution and marketing, for 20th Century-Fox Film Corp., puts it this way: "You know what is really amazing? How do these kids know when these movies open which will be a hit and which a flop? How do they know so quickly not to go to a film before reviews can even appear in the paper or on television? There's an incredible underground out there."

Ivers and Linda Goldenberg, the studio's vice president of field operations and national promotions, took a leisurely six months to develop the "Porky's Plan," a craftily constructed word-of-mouth campaign that included more than 300 free screenings across America. "Police Academy" was sold as if it were a law enforcement "Animal House," which it wasn't, and the film's flirtation with grossness and black humor was stressed. A 30-second TV spot showed a young cop shooting a cat, police trainees reacting to a shower scene and a glimpse of wild stunts involving police cars. Vindication came when the film earned $9 million the first weekend.

"Revenge of the Nerds" presented 20th Century-Fox with perhaps the ultimate test of a hype plan. When the studio showed rough cuts to shoppers in supermarkets, 90 percent said they had no wish to see a movie with such scenes in it. Said one studio source, "Some executives who saw the movie were embarrassed by it and despaired of turning it into a hit." For "Nerds," Brodsky, Sherak and Goldenberg designed a plan that came to be known as "Nerd Chic." In 25 major cities, 20th sponsored "Nerd Awimpics" complete with tacky costumes, TV coverage and surprisingly large crowds. The night before "Revenge of the Nerds" opened in a dozen key cities, radio-promoted screenings were open to anyone dressed as a loser.

The teen-age genre panders to its adolescent audience in other ways as well -- particularly in the editing process. Many of the films were edited in part because of reaction from special previews. "We found that the audience didn't take so well to some things," Kanew says. "For instance, we had a very violent 'Animal House' type scene in 'Revenge' where the fraternity villains completely wrecked the nerds' own frat house. When we showed it, kids were completely turned off; we were able to tell that we had gone way too far. It was cut completely." Maslansky and Wilson of "Police Academy" used far more carefully selected industry audiences to slice their film to its polished cut.

"It was important -- if not crucial -- to screen the rough-cut film for 16-to-21-year-old audiences," says Wilson. "And while I was watching the previews, there were moments when I thought I really should be put in jail for this and moments when I thought it was quite good."